These are Trinity's very best packs for racing. Designed with specifications directly from the "World's Fastest" SPEC and modified class racers. White Carbon LiPo's are the very best packs that could be developed to wear the Trinity name. HC (High Capacity) means the pack has a higher than average milliamp run time. Being an Extreme Pro Level Racing Battery White Carbon Packs are capable of handling a 3C charge rating. For the safest charge and the longest pack life a 1C charge rating is recommended.